Assessing the effectiveness of palliative radiotherapy for painful bone metastases in low- and middle-income countries: A systematic review

Palliative radiotherapy (RT) effectively relieves pain in patients with bone metastases (BMs). Furthermore, several clinical trials, in most cases conducted in high-income countries (HICs), proved that single-fraction RT is equally effective compared to multi-fractionated RT. However, the evidence is scarce regarding low/middle-income countries (LMICs), where the diagnosis of BMs could be later and RT techniques less advanced. Therefore, we conducted a systematic literature review to evaluate the efficacy of palliative RT of BMs in the LMIC setting. A literature search was performed independently by two authors on the PubMed, Cochrane and Scopus databases. Overall, 333 records were screened and after the selection process, 11 papers were included in the analysis. Complete pain response rates ranged from 11.5% to 37.1% (median: 22%) for single-fraction RT and from 0% to 35.1% (median: 19%) for multi-fractionated RT. Partial pain response rates ranged from 23.1% to 76.9% (median: 53.8%) for single fraction RT and from 23.8% to 84.6% (median: 65%) for multi-fractionated RT. Four randomized trials compared single-fraction RT with multiple-fraction RT and none of them showed significant differences in terms of pain relief. Our analysis showed that pain response rates after palliative RT recorded in LMIC are like those reported in studies performed in HIC. Even in this setting, RT in single fraction shows comparable pain response rates to multifractional RT.